I'm using a grohe universal rough in box (the overly large blue one), and had it plumbed in. THe hot, cold and upper supply to the shower head are plastic flex tubing. The downward connection to the tub spout is copper. All 4 connections are threaded connections. So, due to a slight mix up and a stupid design aspect of the box, the tub spout connection will be a bit two deep in the finished wall. It is supposed to be I think 3/8 below the finished surface. Anyhow, it's going to end up slightly more than that. When I realized it was likely to shallow, I called the plumber back and he thought there was enough "play" in the pipe, as in it pulls out a bit. So I've now cement boarded, and about to tile, but using a piece of tile for reference, and connecting the tub spout, I have to pull it out quite a bit. It would work however. (THe tub spout is also a silly design, by hansgrohe, in that there doesn't seem to be any play in it, it has to be exact. THere is a part that pushes into the spout, and sits with a set screw...and there might be play in that, but I don't know , I assume it's supposed to push all the way in?). Anyhow, Im a bit concerned that if I tile the wall and then pull the pipe out far enough to connect it, about the stress/strain on the threaded connection to the mixer box. Is this a valid concern? Since it's a threaded connection and not soldiered, I'm worried the stress might be enough to create a leak there? I asked one other person, and they though the play was enough as well. Am I over worrying about this? Or should I have it redone to a better depth? PRoblem is, I am ready to tile, and extra delay is killing me. IN general, is stress like that a leak creator? or nothing to worry about? Please help! I'm trying to get the plumber to come back to advise, as I need him back anyhow, but Not sure how quickly he'll be able to come!